Fuel-delivery pump for internal-combustion engines and other purposes



March 16,1926. 1,576,826

C. HUGHES FUEL DELIVERY PUMP FOR INTERNAL COMBUSTIO ENGINES AND OTHER PURPOSES Filed March 7. 1923 F/GZ.

Patented Mar. 16, 1926.

'CECIL HUGHES, OF LiLANDRINDQD WELLS, TALES.-

FUEL-DELIVERY PUMP FOR INTERNAL-COMBUSTION ENGINES AND OTHER PURPOSES.

Appli'cationfiled March 7', 1923 Serial No. 623,565.'

To all rv/10m. it may concern Be it known that I, CnoiLHUor-Ins, a sub-- jcct of the King of'England, and residing at Llandrindod \Vells, in thecounty of lRadnor, Wales, have invented Improvements in and Relating to Fucl-Delivery Pumps for lnternal-Combustion Engines and Other Purposes, of which the following is a specification.

This invention relates to means for supplying liquid fuel to internal combustion engines said means being of the kind in and, after a predetermined movement of the plunger in the same direction, to suddenly release the fuel under pressure and permit it to pass through a transfer passage or pipe to the interior of the pump cylinder on the opposite side of the plunger Where it commingles with air and from which. the mixed air and fuel passes out through a suitably arranged outlet.

The invention may therefore be said to consist broadly of liquid fuel supply means comprising a plunger pump by means of which fuel is induced into its cylinder on one side of the plunger by movement of the plunger in one direction the return movement of the'plunger in the opposite direc' tion serving to exert compression on the fuel thereby induced in and, after a predetermined movement of the plunger in the same direction, to suddenly release the fuel under pressure and permit it to pass through a transfer passage or pipe to the interior of the pump cylinder on the opposite side of i the plunger where it commingles with air and from which the mixed air and fuel passes out through asuitably arranged outlet.

The invention is particularly applicable to that type of pump having an air compression arrangement in connection with the neck or part of the pump through which "the 'piunger' passes.

In this type of pump the air compression arrangement may be utilized to supply air released fuel is passed after being subjected to pressure. In a reciprocating piston pump, according to one embodiment of this invention, the intake or suction inlet is at a point on the side of the cylinder intermediate its ends; and the delivery conduit is at one end. A com minicating pipe connects together two points of the cylinder, through which the liquid is transferred from'one side of the plunger to the other in the active stroke of the pump. That is, the liquid drawn into the outer end of the cylinder by the intake or suction stroke 'of the plunger, is forced in the forcing action of the plunger, out of this end by the plunger through or by way of said'transfer pipe, :to the opposite or delivery side of the plunger, and air is forced by the compressor which be of the diaphragn'i type, into the delivery end of the pump, and the iiquid is atomized and the mixture forced to the engine intake conduit. and delivered through a nozzle or the like into it, where it is mixed with the further quantity of air required.

The invention is illustrated in the accompanying drawings, in which:

Fig. 1 is a sectional view illustrating the improvement.

Fig. 2 is a similar view of a modification. Fig. 3 is a similar view of a further modification. i

1 is the pump cylinder, is the pump piston, and is its piston rod. it is the intake or suction pipe of the pump,- disposed between the twoends of the cylinder, is

the deivery pipe entering the cylinder near its end, at which the pistonv rod 3 is .connected to the piston, and 6 is the transfer 'iipe, communicating with the cylinder at the outer end, and at a point between the points where the suction and delivery pipes or conduits i enter the cylinder.

7 is the vessel of the diaphragm compressor, of which 17* is the air inlet valve. through which the piston rod 3 passes and upon the upper end of which flexible diaphragm 8 is provided, to which the piston rod 8 is connected by a nut or flange?) in the known way. In the case shown, the diaphragm is adapted to be operated by an eccentric 11, operating a lever 12, whlch is connected with the upper end of the piston rod 8.

Communication is provided between the vessel 7 and the top of the pump cylinder, and this may be effected by a slight clearance or space between the piston rod and the upper end of the cylinder 1, and n the diaphragm compression stroke, which is simultaneous with the active piston stroke air is forced to the upper or piston rodend of the cylinder with the effect hereafter described. v r

In action,-assuming the piston 2 to beat the upper end of its stroke, and the diaphragm 8 also atthe upper end of itsstro ke, and they are moved idown in their active strokes, when the top of the piston uncovers the upper or port end of the pipe 6, the pressure in the lower end of the pump cylinder will be at its maximum, and owing to its pressure the .liquid rushes with great velocity into the space above thepiston, which will contain air and atomized petrol, forced down into it through the space between the piston rod 3 and the cylinder head, by the pressure in the chamber 7 created by the. diaphragm, which willbe greatest at this moment, and it will be broken up or atomized.

After the uncover-111g ofthe upper end of the pipe Gby the piston,. and the atomization ofthe fuel, the fluid by its pressure will be delivered to the intake of the cylinder of the. engine, sayv where thecarburetter isusually placed, and suppled withfurther air asusual. That is, at the moment of release by the piston, and afterwards, the pressure pushes all before it, and forces it. .to the point of use through pipe 5 as specified.

The pressurein the vessel 7will also have forced any liquid in the vessel 7 through the pipe 15. which is without a. valve back to the petrol supply tank. This pipe; 15, being suitably choked somewhat, while it will,

carry away all liquid which .may have reached and deposited in the vessel 7 will have such a pressure in it created by the downstroke of the diaphragm, that air will be forced by it d-ownbet-ween the rod and cylinder cylinder. I i

In the return strokeof the pump piston, the fluid in the cylinder above it is partly forced back into the vessel 7 between the piston rod and cylinder head, and partly into the pipe I 'llhedeliveryof fuel from-the-pump at the engine is timed to coincide with each induction .strokeof the engine,,and itswfinal delivery to, the engine isthrough a vjet or gets, 7 In the modification shown in Figure 2,

body, as stated, into the top of the.

below the end of the cylinder 1, a spring retained device is provided so that the capacity of the chamber is automatically extensible.

In the case shown, this device consists of a flexible diaphragm 16, normally pressed up by a spring 17 within the casing 18.

This allows for the liquid or fuel to be put under pressure, which when the charge is liberated as above described, reacts on the fluid and continues to react, while it is delivered from one side .of the piston 2 to theother, that is follows it up; and thus the moment the transfer port (3 is uncovered by the piston, the strong spring 17 forces the fuelforward. from the enlarged cylinder chamber 19, into the top as described.

The tension of the spring 1.7 is adjustable by a screw. support 20 which supports thev spring and screws in and. out the casing 18.

lVith reference to. the modification.shown in'Figure 8, there is used in connection with thelowerpart of thepump, means for admitting a regulated quantity of air, namely,

it is provided with a non-return valve 21, and an ordinary regulating cock 22, so that a. certain amount of air w'll be drawn into the pump as well as liquid fuel, which will ,mix with it, and the two will be delivered through the transfer conduit (5 as above described, and. n'roreover this air inlet will cover or. control to a considerable extent the quantity and the degree of vacuunrin the lower end. of the cylinder on the up or suction stroke of the piston.

Bythis means, the actual amount of fuel entering the cylinder is controlled, and thereby the actual delivery of any required quantity, both the air and. fuel so introduced are compressed together in a state of almost complete atomized fuel. 7

:Further, a non-return valve :2?) is provided on the delivery port 5 of the pump; and also a pipe 24 with a non-return valve 25, 011 it connects the interior of the diaphragm chamber 7 with the top end of the cylinder, so that the air which is drawn into the chamber 7 and compressed .on thedown stroke of the diaphragm 8 is admitted into the top .or :the pump cylinderon the downward .stroke of" the pump piston until the point higher degree of atomization of the fuel.

The pressure in the top of the cylinder is at its. highest-immediately the transfer port is uncovered, at which. point also thepressure of the air in the diaph 'agm chamber is at its highest.

What is claimed is l. A. fuel supply means including a cylinder having a fuel inlet, a fuel outlet, a plunger operative in the cylinder to draw F fuel mto the cylinder through the inlet .on

a predetermined movement of the piston and to exert pressure on the contained fuel in the opposite movement of the piston, means for establishing communication between that portion of the cylinder communicating with the inlet and that portion of the cylinder communicating with the outlet, said means being closed against communication with that portion ofthe cylinder communicating with the outlet until the piston has reached a predetermined point in its movement and exerted a corresponding pressure upon the fuel in the cylinder, and means for supplying air to that portion of the cylinder communicating with the outlet.

2. A fuel supply means including a cylinder having a fuel inlet, a fuel outlet, a plunger operative in the cylinder to draw fuel into the cylinder through the inlet on a predetermined movement of the piston and to exert pressure on' the contained fuel in the opposite movement of the piston, means for establishing communication between that portion of the cylinder communicating with the inlet and that portion of the cylinder communicating with the outlet, said means being closed against comn'iunication with that portion of the cylinder communicating with the outlet until the piston has reached a predetermined point in. its movement and exerted a corresponding pressure upon the fuel in the cylinder, and means operative in the movement of the plunger for supplying air to that portion of the cylinder communicating with the outlet.

3. A fuel supply means including a cylinder having a fuel inlet, a fuel outlet, a plunger operative in the cylinder to draw fuel into the cylinder through the inlet on a predetermined movement of the piston and to exert pressure on the contained fuel in the opposite movement of the piston, means for establishing communication between that portion of the cylinder communicating with the inlet and that portion of the cylinder communicating with the outlet, said means being closed against communication with that portion of the cylinder communicat ing with the outlet until the piston has reached a predetermined point in its movement and exerted a corresponding pressure upon the fuel in the cylinder, and a diaphragm pump operative in the movement of the plunger for supplying air to that portion ofthe cylinder communicating with the outlet.

l. A fuel supply means including a cylinder having a fuel inlet, a fuel outlet, at plunger operative in the cylinder to draw fuel into the cylinder through the inlet on a predetermined movement of the piston. and to exert pressure on the contained fuel in the opposite movement of the piston, means for establishing communication between that portion of the cylinder communicating with the inlet and that portion of the cylinder communicating with the outlet, said means being closed against communication with that portion of the cylinder communicating with the outlet'until the piston has reached a predetermined point in its movement and exerted a corresponding pressure upon the fuel in the cylinder, and a diapln'agm pump operatively connected with the plunger and serving during the suction stroke of the plunger to draw air into the pump and in the operative stroke of the plunger to force said air into the cylinder in that portion communicating with the outlet.

5. A liquid fuel supply means, including a chamber having an air inlet, a'diaphragm operative in the chamber, a pump cylinder connected to and having communication a with the chamber, a piston operative in the cylinder and having a fuel inlet end and a fuel outlet end, a bypass from the inlet end of the cylinder to the outlet end thereof, and a piston rod connecting said piston and diaphragm.

In testimony whereof I have signed my name to this specification.

CECIL HUGHES. 

